Artificial tooth



Dec. 9, 1941. s. MYERSON ARTIFICIAL TOOTH Filed April 27, 1938 "DEN. y

jzvev-zziar Z a 53371 2177 Patented Dec. 9, 1941 UNITED STATES-PATENTOFFICE ARTIFICIAL TOOTH Simon Myerson, Brookline, Mass Application April27, 1938, Serial No. 204,512

1 Claim. '(Cl. 3210) This invention relates to improvements inartificial teeth and backings therefor.

The purpose of the invention is to provide an artificial tooth having agingival contact of porcelain, and also an occlusal or biting portion ofporcelain. By the construction of my tooth and backing I have providedan extremely strong and easily workable porcelain member and backingmember having, in addition, the advantages of i wide range ofapplication in the restoration of lost teeth as well as preserving ahighly aesthetic appearance. For convenience of description I shalldesignat the porcelain or the like member as a tooth; and

the metallic or like member as the backing; and

that portion of the tooth to which the backing is to be fitted as thebody portion; and the remainder of the tooth as the crown portion. It

follows as a matter of course then that the gindesignated throughout theseveral views by the" same reference characters.

Fig. 1 is a side view of a posterior tooth made in accordance with myinvention;

Fig. 2 is a buccal view of such a tooth;

Fig. 3 is a lingual view of such a tooth;

Fig. 4 is a perspective view of one type of backing to be used with atooth shown in the preceding figures;

Fig. 5 is a perspective view of an optional backing;

Fig. 6 is a side view of the assembled tooth and backing, after thebacking has been completed as herein described;

Fig. 7 is a buccal view of a bridge in the mandible extending from thefirst molar to the cuspid, this bridge carrying two bicuspid dummiesmade in accordance with this invention;

Fig. 8 is a top view of the bridge shown in Fig. 7;

Figs. 9, 10 and 11 are sections respectively on lines 99, IIJI0 and Il-Hof Fig. 2;

Figs. 12 and 13 are sections on lines |2l2 and |3-| 3 respectively ofFig. 6;

Fig. 14 is a side View of an anterior tooth; and

Fig. 15 is a perspective view of a backing therefor.

As shown particularly in Figs. 1, 2 and 3, an artificial tooth formed inaccordance with this invention may be provided with a smooth body orbase I, which tapers slightly from its upper or 5 of occlusal enddownwardly toward its gingival portion 5 on all of its faces. This toothis provided with a crown 9 having a buccal face 2 and a lingual face 3;the upper part of the crown obviously provides the occlusal face 4 ofthe tooth. At each side of the tooth, the recessed base portion or bodyportion may be provided with an extension 6 which may extend to theocclusal face, thus separating the buccal portion 2 and the lingualportion 3 of the crown, these portions of the crown being offsetrelative to the base and its extensions 6. The crown portion 2 is thusprovided with a shoulder or margin 1, while the crown portion 3 isprovided with a similar shoulder 1*. These shoulders, as shown in Figs.1, 2 and 3, may extend downwardly from the occlusal face 4 of the tooth.Thus the shoulder I may extend downwardly along the mesial portion ofthe tooth toward the gingival portion across the buccal face and to theocclusal surface on the distal aspect of the tooth. The margin orshoulder I may extend from the occlusal face of the tooth on its mesialaspect toward the gingival portion of the tooth and across the lingualface to the occlusal surface on the distal aspect of the tooth. Ifdesired, the shoulders may be slightly undercut. It is evident that thecrown portions 2 and 3 provide surfaces which are continuous with theocclusal surface 4 of the tooth.

A tooth of this type may receive a backing H] with a ring-like orannular lower portion substantially or preferably entirely to encirclethe body I of the tooth. This backing has a buccal aspect II and asubstantially higher lingual aspect l2. The backing is also providedwith-lateral extensions I3 to fit within the recessed portions 6 of thetooth. The backing may be provided with front and rear flanges l4 and Madapted to engage the shoulders 1 and 7 respec-- tively; the flanges arepreferably free of sharp corners at the regions where the extensionsv i3join the annular body portion. The backing is provided with a lower edgeor gingival margin I6 substantially to conform to the shape of thegingival portion of the tooth.

Fig. 5 illustrates an optional form of backing Hi with buccal andlingual aspects ll and I2 respectively and with extensions l3 In generalthis backing is similar to that shown in Fig. 4, but the flanges l4 andId are omitted, and relatively thick upper edges l3 and l3 are providedto engage the shoulders I and 7 respectively of a tooth.

Fig. 6 shows the manner in which a backing the type shown in Fig. 4 maybe assembled with a tooth of the type shown in Figs. 1, 2 and 3. In thisfigure the buccal and lingual portions of the backing are shown indotted lines and are designated respectively by numerals II and I2. Asshown, a body of solder It may be disposed beneath and between theflanges I4 and I4; rather than solder, casting gold or other materialmay be employed to complete the backing. The lower, exposed portion ofthe body is designated by the numeral E9 in this figure.

Figs. '7 and 8 show natural teeth 29 and 2!, namely, a first molar and acuspid used as abutments to carry the artificial teeth 22 and 23. Inlays24 and 25 are shown in dotted lines in Fig. '1, being soldered orotherwise joined to the backings. The exposed gingival portions of thebases of the teeth are designated by the numerals 1-9 in Fig. 7 and theexposed buccal portionsofthe crowns of these teeth by the numeral 9. Asshown in Fig. 8, solder w or the like-maybe employed to join theextensions l3 of .the .backings.

In Fig. 14, corresponding reference numerals designate parts similar tothose shown in Fig. 1, except that the incisal portion of the anteriorteeth .is designated by reference character 4.

Fig. 15 shows a backing Ni which may be employed with such a tooth .andwhich is provided with a 'buccal aspect H and a lingual aspect 152 aswellasextension 13 In practice, I use a molar or bicuspid tooth,

- asshown for example in Fig. 1, and a thin backing such as isrepresented in Fig. 4,'w;hich has ibeen made to closely fit theporcelain tooth body. In the manufacture of my tooth in porcelain, itis;r,eadily-feasible to control the size of the tooth to fairly constantdimensions with occasional maximum variations of from .005 to .010 of an.inch. Moreover, the backing may-be slitat any :point so that it may betaken up to fit the tooth iif loose, or if 'itbe tight it can be readilystretched by light tapping with a hammer, or be burnished,

as preferred. I prefer to use the closed backing :as illustrated in thefigures,asthe slight'stretchting, where necessary, is so easilyaccomplished. In selectingteeth for the case, I select teeth "that gofreely into their places and which require a .Lminimum of gingival andocclusal grinding. Having fitted the teeth into their position, I'then'burnish the backing andthe flanges (if the -flange type of backingis used) and theextend- .iing .portions to fit the body and shouldersand the crown margins.- Then "I swa'ge the backing 'to the toothandthen'complete the backing "by :waxing to the proper :contours,thereafter re- :moving the tooth :from its backing, :the investing andcastingbeing done in the usual manner. Itwill'be-seen' that the backingforms-a strong and rigid encasement for the tooth body and that theextensions provide convenient "and properly located ineans-for joiningthe -backing -members of the teeth :to any typeo'f abutment 'orto otherbacking members andthat the extensions-of the backing form valuablereinforcement to the rest o-fthe backing in resistance to stronglingual-buccal forces of mastication; and "that they also provide the.utmostmechani- .cal advantage against these iforcesbecause the juncturew can take place close to, -if not exactly .atthe same level .at which,theforces areapplied.

Also, this construction provides a hygienic advantage in "that the-juncture;may.be made as .yfar easmeeessary; from the gum tissue and,makes -a more rigid one, as follows: Adapt the pliable backing in themanner already described, set upon this backing a rigid backing, leavingmargins of the pliable backing exposed, remove, and

solder the two together.

In making a bridge or denture with my dummies, any type of abutments maybe used, including removable types. In the bridge which I have chosenfor illustration, inlay abutments have been used. The inlay abutmentsare fitted 'to place and a wax bite is taken with the jaws in properfullcentric occlusion. After this an impression is taken; the abutmentsshould come oif with the impression or be placed in he impression shouldthis be necessary. Articulated models should be poured in the usualmanner. The individual dummies ,should .each be separately fitted andcompleted, then fixed in place with wax. The teeth should be oiledbefore being fixed in place upon the model, so that the wax will stickto the backings and not to the teeth. The teeth should then be removedfrom the backings and. the bridge invested and completed by solderingthe members together as is .customary in the art. Ifthe gingivalsurfaces of the teeth have been ground, they should be re- 1 glazedbefore they are'cemented to their backings.

The completed bridge will be seen to have many advantages over the priorart. The porcelain members only of the dummies contact the gingiva. Eachindividual dummy-can be finished to smooth-and natural contours and befree from food-retaining poekets. The gold or othermetal membersarefreely-accessible to cleaning Witha tooth brush or other means, and canquite readily be kept clean. The construction secures the maximumstrengthfor-the amount of metal used and also h maximumt ethinhe-porcelai tooth, the porcelain tooth also having an exposed occiusalof porcelain. ;It be seen that lower ;molars and .bicuspids :as Well.;asanteriors,

made after my invention, will :show very little metal, that part of thebacking which crOsses the buccal orlabial aspects of the tooth being{entirely invisible in lower bridges. In upperteeth this is not true in;all cases, especially with .relation totheanterior teeth, as somepeople expose their anterior teeth much more :thanothers ,do. Theadvantages gained, however, more than offset .this possibility. In cases.where it iis'indi- .cated, one .may use a metal of vless conspicuouscolor than thegold alloysordinarilyused.

Although I have not .shown a molar dummy in the illustrations, it isobvious that theconstruction mightrbe similar to that illustrated, in

all the figures except Fig. '14.

It should-be understood thatthe present-disclosure is for the purposeofdllustration only and that-this invention includesall'modifications-and equivalents which fall within the scope of theappended. claim.

,an annular .lower ,portion for substantially ,en-

tirely encircling the base of a tooth, said backing having a lower edgeto conform to the gingival portion of a tooth, said backing havingextensions to project substantially to the occlusal surface of the toothat the mesial and distal sides thereof, the backing being provided witha flange extending along the front edge of one of said extensions andalong the upper edge of the buccal portion of the backing and thencealong the front edge of the opposite extension, the backing having asecond flange extending along the rear edge of one extension, along theupper edge of the lingual portion of the backing, and then along therear edge of the other extension, the buccal portion of the backinghaving a smaller depth than its lingual portion.

SIMON MYERSON.

